Plain English Meaning

Flying done after dark. Because the pilot can see far less of the world outside the airplane, night flying has its own rules, equipment requirements, and techniques that differ from day flying.

Full Definition

Flight activities conducted during the period from the end of evening civil twilight to the beginning of morning civil twilight, requiring specific pilot currency, aircraft equipment (position lights, anti-collision lights, instrument lighting), and techniques adapted to reduced visual cues, altered depth perception, and limited outside visibility.